| 摘要 |
A combined depth-control and wing-lift hydraulic circuit is disclosed. The circuit is preferably used in combination with a farm implement having a tool bar. The tool bar is horizontally disposed relative to the ground, and is carried by the implement. The hydraulic circuit comprises means to raise and lower the tool bar relative to the ground, thereby to effect depth control. The tool bar includes pivotally connected wings. Each wing carries an associated wing wheel. The hydraulic circuit includes means for causing rotative movement of each wing about its associated tool bar pivot between a substantially horizontally-disposed position and a substantially vertically-disposed position, relative to the ground, and for further causing each wing to be selectively disposed at one of these positions, thereby to effect wing lift. Each wing wheel is coupled to, and is distally spaced from and located beneath, its associated wing structure when such wing is in the substantially horizontally-disposed position. Also, each wing wheel is outwardly spaced from its associated wing structure when the wing is in the substantially vertically-disposed position. The hydraulic circuit further includes means for causing each wing wheel to be drawn inwardly toward its associated wing structure when such wing is in the substantially vertically-disposed position, thereby to effect a special "wheel-tuck" feature of the present invention. The hydraulic circuit can additionally be used to control operation of a marker arm for forming marker furrows. |
